Culinary Terminology - O

Oeuf: Egg. A recipe for oeufs farcis (stuffed eggs: remember farce?) is here:

Oignon piqué: French for "stabbed onion". With a clove, tack a bay leaf with onto a peeled onion. Stabbed onions are used to flavor soups and sauces. 

Oignon brûlé: French for "burnt onion" (think of créme brûlé, and the burnt sugar on top). Charred half onions give color and flavor to stocks and sauces. 

Oblique: this is a type of cut, with two angle-cut sides.